M.F. Leung
Pasadena City College,
United States
Keywords: nanofabrication, surface roughness, atomic layer etching, simulation
Summary:
Nanofabrication will play a prevalent role in the next generation of microelectronic and quantum devices such as transistors, qubits, and optical resonators. Nanoscale roughness on surfaces and interfaces often becomes a limiting factor in device performance by limiting the device quality factor. A promising tool for reducing nanoscale surface roughness is atomic layer etching (ALE). ALE makes use of self-limiting cyclic reactions to etch material layer by layer, resulting in a smoother surface with each cycle. ALE can often be used to control surface roughness to the order of a few Angstrom. While the mechanisms are not fully understood, some models, such as a uniform front propagation model based on the surface gradient and a diffusion model dependent on the surface curvature, have been recently developed to better understand the ALE process. In order to explore these models further, finite-difference simulations based on this model have been carried out on both 1D and 2D surfaces. The resulting surfaces can be compared to different ALE processes with different etching chemistries to better understand the smoothing process in ALE.